title: Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions.
abstract: OBJECTIVE
  This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions.
  
  
  METHODS
  Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually.
  
  
  RESULTS
  The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites.
  
  
  CONCLUSIONS
  The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.
authors.affiliation: Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Raquel Venâncio Fernandes
authors.initials: RV
authors.lastname: Dantas
authors.forename: Hugo Ramalho
authors.initials: HR
authors.lastname: Sarmento
authors.forename: Rosângela Marques
authors.initials: RM
authors.lastname: Duarte
authors.forename: Sônia Saeger
authors.initials: SS
authors.lastname: Meireles Monte Raso
authors.forename: Ana Karina Maciel
authors.initials: AK
authors.lastname: de Andrade
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Dos Anjos-Pontual
keywords: Composite Resins; Computer-Assisted Radiographic Image Interpretation; Dental Digital Radiography; X-ray Film